ABCL/R2 is a second generation version of ABCL/R, designed for the Hybrid Group Architecture. It was produced at the Tokyo Institute of Technology in 1992, and has almost all the functionality of ABCL/1. It is written in Common Lisp. As a reflective language, its programs can dynamically control their behavior, including scheduling policy, from within a user-process context.

ABCL/c+ is an object-oriented concurrent language, a variant of ABCL/1 based on C instead of Lisp. This language is often referred of as C+, but must not be mistaken for C or C++. C+ was created by professor Akinori Yonezawa, winner of the Dahl-Nygaard Prize in 2008. The Dahl-Nygaard Prize is the world’s most prestigious prize in the field of object-orientation.